Sheet conveyor for automatic copying machines

ABSTRACT

A sheet conveyor device for automatic copying machine where a suction tank has rollers positioned therearound for endless belts to be driven thereon, and suction holes are located in said tank between the belts. A guide sheet extends around most of the suction tank and is closely spaced thereto so that a sheet of paper can be passed between said guide sheet and the belts and held against the belts by the suction.

United States Patent 151 3,687,548 Yug r 51 Aug. 29, 1972 [54] SHEETCONVEYOR FOR AUTOMATIC 2,206,333 7/1949 Robertson ..355/9l COPYINGMACHINES 2,584,401 2/ 1952 Thralls ..355/76 3,105,107 9/1963 Klausner..355/68 X [72] Kwayash Japan 3,152,528 10/1964 Pendry .355/49 x [73]Assignee: Kabushiki Kaisha Ricoh, Tokyo, 3,359,879 12/1967 Hamlin..355/73 X Japan 3,521,538 7/1970 Escoli ..355/91 X [22] Film: Sept-'231969 Primary Examiner-Samuel S. Matthews [2]] Appl. No.: 860,251Assistant ExaminerMonroe H. Hayes Attorney-Burgess, Ryan and Hicks [30]Foreign Application Priority Data 57 ABSTRACT Sept. 27, 1968 Japan..43/69425 A Sheet conveyor device for automau'c copying machine where asuction tank has rollers positioned U'S- Cl- ..355/76, therearound forendless belts to be driven thereon 355/91 and suction holes are locatedin said tank between the [51] 1131. CL ..G03b 27/62 belts A guide sheetextends around most of the suc- Fleld of Search tion tank and is closelyspaced thereto so that a sheet /9 of paper can be passed between saidguide sheet and the belts and held against the belts by the suction.[56] References Cited 7 4 Claims, 3 Drawing Figures UNITED STATESPATENTS 601,8 83 4/1898 Schwarz .,....35 5/9 1 SHEET CONVEYOR FORAUTOMATIC COPYING MACHINES BACKGROUND OF THE INVENTION The presentinvention relates to an automatic copying machine and more particularlya sheet conveyor for automatic copying machines.

It is very difficult in automatic copying machines to transport securelyand uniformly sheets such as tracing paper which have a very smallthickness, a poor strength and a tendency of being easily curled,without causing any damage to them. This difficulty is met not only inthe case of transporting along a planar surface but also in the case ofconveying a curved surface having a small radius of curvature. Thedifficulty is increased especially in the latter case.

As a device for conveying such sheets or the like of the characterdescribed above, there has been used a device wherein a plurality ofconveyor belts are spaced apart from each other upon a suction tankhaving suction holes so that the sheets or the like may be firmlypressed against the conveyor belts by the suction of the air into thesheet or the like does not seal the suction holes, the surrounding airis unnecessarily sucked through these holes, so that the suction of thetank is reduced and the sheet or the like cannot be firmly pressedagainst the conveyor belts as desired.

One of the objects of the present invention is therefore to provide adevice which can ensure the positive, secure and uniform transportationof the sheets or the like in the conveyor system of the type describedabove.

Another object of the present invention is to provide a sheet conveyordevice of the type described above which enables the sheets or the liketo be transported along a vertical surface and a ceiling.

SUMMARY OF THE INVENTION According to the present invention, theconveyor belts are closely covered with a guide sheet having a widthequal to or slightly larger than the over-all width of the conveyorbelts. The sheet or the like is transported by the conveyor belts underthe guide sheet while the sheet or the like is firmly pressed againstthe belts by the above described suction. Since the guide sheet isclosely pressed against the conveyor belts at the portion where no sheetor the like is interposed therebetween, the air to be sucked into thetank through the suction holes upon which is not passing the sheet orthe like is remarkably reduced in quantity. This means that the sheet orthe like is sucked and pressed against the conveyor belts with anincreased force. Thus, the sheet or the like may be positively, securelyand uniformly transported without causing any damage in a wellsafe-guarded manner.

The above and other objects, features and advantages of the presentinvention will become more apparent from the description of oneillustrative embodiment thereof with reference to the accompanyingdrawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a diagrammatic view forexplanation of a sheet conveyor device in accordance with the presentinvention;

FIG. 2 is a fragmentary side view thereof with parts broken away; and

FIG. 3 is a cross sectional view thereof illustrating thesheet or thelike being transported.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIGS. 1 and 2, anopening 2 is formed at a suitable portion of one side of a suction tank1 and is connected to one end of a conduit pipe 3 leading to a suctionpump (not shown) so that the air within the tank is always dischargedtherefrom, thereby maintaining the pressure negative relative to theatmospheric pressure. An endless belt 4 is wrapped over rollers 5,6,7and 8 so as to be advanced in the direction indicated by the arrowaround the tank 1.

The endless conveyor belt 4 is comprised of a plurality of equidistantlyspaced apart belts and suction holes 9 are formed in the side wall ofthe tank 1 in opposed relation with the spaces between the belts orstrips. Thesuction holes 9 may be of slit shape.

A guide sheet 10 is made of a material such as plastics or sheet metalshaving a high-grade surface smoothness and a better air-tightness andincapable of generating electrostatic charge (electrification). Theguide sheet 10 is disposed outwardly of the belt 4.

When a sheet of paper 11 is inserted between the conveyor belt 4 and theguide sheet 10 through an inlet in the direction indicated by the arrowin FIG. 1, the sheet 11 is transported by the conveyor belt 4. In thiscase, sheet 11 is sucked and pressed against the conveyor belt 4 by theair sucked into the suction tank 1 through the suction holes 9 formed inthe side wall thereof. This is illustrated in FIG. 3. That is, the sheet11 being conveyed by the conveyor belt 4 is subjected to the suction atthe spaces between the belts by the air sucked into the tank through thesuction holes 9. Therefore, the sheet 11 may be securely held upon theconveyor belt while it is advanced. There is no suction in the spacebetween the conveyor belt 4 and the guide sheet 10, so that thetransportation of the sheet 11 will not be adversely affected even whenthe surface of the guide sheet 10 is rather rough.

Only the upper end portion 12 of the guide sheet 10 may be held inposition whereas the lower end may be free upon a support 13 when thecopying machine is in inoperative position because when the machine isonce operated, the guide sheet 10 may be tightened upon the conveyorbelt 4 due to the tension applied to the guide sheet 10 from theconveyor belt 4 and the suction described hereinabove.

There has been used an arrangement and construction in which a guideplate is spaced apart from the conveyor belt 4 by a small distancewithout employing the guide sheet 10 of the character described above.However, in this case, it is not ensured that the sheet 1 1 is securelypressed against the conveyor belt 4 so that the sheet is for examplecurled, thus resulting in the difficulty in transporting the sheet orthe like 11 smoothly without causing any deformation thereof. There hasbeen also proposed a method in which another conveyor belt is extendedover the conveyor belt 4 so as to be driven together. However, thetension present in the exterior conveyor belt will act upon the sheet orthe like to be transported. This is not preferable and the constructionis complicated.

However, according to the present invention, the sheet or the like ispressed securely against the conveyor belt by the suction due to thenegative pressure in the suction tank so that the sheet may be smoothlytransported not only along the planar surface but also the curvedsurface having a small radius of curvature. Furthermore, sheets whicheasily tend to curl may be transported in a well safe-guarded manner andmay be transported even along the ceiling. Since the guide sheet of thepresent invention is attracted toward and seals the suction ports otherthan those acting upon the sheet being conveyed, it is positivelyprevented that the air is unnecessarily sucked through these idlesuction holes into the suction tank, thereby decreasing the negativepressure within the tank.

The suction only acts upon the sheet 11, not upon the guide sheet 10, sothat there is no special acting therebetween so as to adhere them. Thus,the guide sheet will not adversely affect the transportation of thesheet 1 l.

Preferably, the guide sheet is made of a transparent material so thatthe transportation of the sheet can be checked from the outside.

It will be, of course, understood that the device in accordance with thepresent invention is not only applied to an automatic copying machinebut also to any other conveyor system or the like.

I claim:

1. A sheet conveyor device for passing a sheet of paper through anautomatic copying machine comprismg a suction tank mounted within themachine and having an end area including a feed portion and an exitportion for said paper;

a plurality of rollers spaced around the periphery of said suction tankand extending outside of the periphery of said suction tank;

a plurality of endless belts having a predetermined total transversedimension and mounted to be driven on said rollers, said beltslocated'on said rollers to provide a predetermined spacing area betweenadjacent belts;

individual groups of suction holes formed in said suction tank, eachindividual group located solely in one of said predetermined spacingareas respectively;

a guide sheet of a flexible nature located in the machine, said guidesheet having vertically spaced and aligned inlet and outlet end portionsadjacent said end area of said suction tank, said guide sheet having aconfiguration to be disposed outwardly of an adjacent to said endlessbelts;

said guide sheet projecting inwardly into the machine from said end areaand extending around said plurality of endless belts from said feedportion to said exit portion; and

said guide sheet having a transverse dimension greater than saidpredetermined total transverse dimension of said plurality of endlessbelts whereby the paper passing through the machine between said guidesheet and said belts is held against said belts by suction actingthrough said holes.

2. A sheet conveyor device according to claim 1 in which said inlet endportion of said guide sheet is ed th m e and l ated verticall bove 221outl t enfi pgrfii and said outlet end p r on is positioned to movefreely with respect to said machine.

3. A sheet conveyor according to claim 2 in which an element is locatedwithin the machine to provide a support for said freely movable outletend portion of said guide sheet.

4. A sheet conveyor according to claim 1 in which said transversedimension of said guide sheet is such that its outer transverse edgeextends further outwardly than an outermost located belt in saidplurality of endless belts.

1. A sheet conveyor device for passing a sheet of paper through anautomatic copying machine comprising a suction tank mounted within themachine and having an end area including a feed portion and an exitportion for said paper; a plurality of rollers spaced around theperiphery of said suction tank and extending outside of the periphery ofsaid suction tank; a plurality of endless belts having a predeterminedtotal transverse dimension and mounted to be driven on said rollers,said belts located on said rollers to provide a predetermined spacingarea between adjacent belts; individual groups of suction holes formedin said suction tank, each individual group located solely in one ofsaid predetermined spacing areas respectively; a guide sheet of aflexible nature located in the machine, said guide sheet havingvertically spaced and aligned inlet and outlet end portions adjacentsaid end area of said suction tank, said guide sheet having aconfiguration to be disposed outwardly of and adjacent to said endlessbelts; said guide sheet projecting inwardly into the machine from saidend area and extending around said plurality of endless belts from saidfeed portion to said exit portion; and said guide sheet having atransverse dimension greater than said predetermined total transversedimension of said plurality of endless belts whereby the paper passingthrough the machine between said guide sheet and said belts is heldagainst said belts by suction acting through said holes.
 2. A sheetconveyor device according to claim 1 in which said inlet end portion ofsaid guide sheet is secured in the machine and located vertically abovesaid outlet end portion, and said outlet end portion is positioned tomove freely with respect to said machine.
 3. A sheet conveyor accordingto claim 2 in which an element is located within the machine to providea support for said freely movable outlet end portion of said guidesheet.
 4. A sheet conveyor according to claim 1 in which said transversedimension of said guide sheet is such that its outer transverse edgeextends further outwardly than an outermost located belt in saidplurality of endless belts.